Germicidal compositions



Patented Nov. 29, 1949 GERMICIDAL COMPOSITIONS Harold G. Kollofi, Kalamazoo, Mich, assignor to The Upjohn Company, Kalamazoo, Mich., a

corporation of Michigan No Drawing. Application October 28, 1944, Serial No. 560,906

6 Claims.

This invention relates to germicidal compositions and is particularly directed to a mixture of a long-chain alkylamine salt and a mercurial.

Certain of the alkylamines and particularly those containing long-chain structures of eight or more carbon atoms are known to exert a germicidal effect upon certain micro-organisms. However, the concentrations of these compounds required for use as general germicidal and disinfectant materials is high if control is to be obtained against such representative and resistant bacteria as Staphylococcus organisms. Their use has been limited in spite of the fact that they had been widely publicized as comparatively non-poisonous substitutes for the more conventional mercurial type germicide and disinfectant.

Similarly the mercurials are recognized as having limitations in germicidal use. Not infrequently, at the concentrations required for effective control of micro-organisms, these materials are very toxic to humans and may also be corrosive to the skin. Much interest has been developed in the search for substitutes therefor.

It is an object of the present invention to provide compositions adapted for germicidal, disinfectant, and bactericidal use which will be more effective against micro-organisms generally than the amine and mercury products heretofore employed. It is a further object to supply such a composition which will be effective against Staphylococcus organisms and more particularly Staphylococcus aureus. Other ob- Jects will become apparent from the following specification and claims.

According to the present invention, it has been discovered that compositions including a longchain alkylamine salt and a water-soluble mercuric salt are much more effective against bacteria and particularly Staphylococcus organisms than either the amine salt or the mercuric salt alone. In such combinations these two classes of germicidal materials appear to exert a co-operative or synergistic effect, whereby a, composition containing both is effective to a degree greatly in excess of what might be anticipated from a knowledge of the germicidal activities of the individual components of such composition. At the high dilutions of such mixture found effective the hazards normally attendant in-the utilization of the water-soluble mercuric salt are greatly reduced. Furthermore, the combination appears to be more effective against a wider variety of organisms than can be controlled with either constituent alone.

The long-chain alkylamine salts employed in accordance with the present invention are those containing at least one alkyl radical of eight or more carbon atoms attached to the amino nitrogen. The preferred compounds are those in which the alkyl radical is straight chain in configuration and particularly of the group consisting of normal-dodecyl, normal-tetradecyl and normahhexadecyl radicals.

Any suitable mercury salt, preferably watersoluble, ma be employed in combination with the acid salt of the long-chain alkylamine provided only that such mercury derivativ does not form a precipitate with the amine when the composition is dissolved in water, alcohol, wateralcohol mixtures, or other liquid carrier.

The amounts of alkylamine salt and mercurial adapted to be combined to form compositions having the desired properties vary somewhat with the particular. organism to be controlled and the exact nature of the amine salt or mercurial selected. Three parts by weight of the amine salt are generally combined with from one to nine parts of the mercurial. Best results have been obtained when three parts of the amine salt are employed in combination with from two to four and one-half parts of mercurial. The latter range of "proportion constitutes a perferred embodiment of the invention.

The new germicidal compositions may be employed in any suitable form. In a preferred embodiment, the combination of toxicants is dissolved, or otherwise dispersed, in an alcohol or other organic solvent, water, or mixture of water and solvent to produce a germicidal tincture or solution. If this liquid composition is to be used as a concentrate, a relatively high proportion of i the toxicant mixture may be incorporated therein. If the liquid is to be employed for germicidal purposes without further modification only a small fraction of one percentum of the toxicant combination need be dissolved therein. Generally, from 0.01 per cent to 10 per cent of dissolved toxicant yields a satisfactor concentrate and o e part per forty thousand or less is effective germicidally in the ultimate dilution, as illustrated by tests according to the F. D. A. method hereinafter mentioned.

Further embodiments of the invention include the incorporation of the toxicant mixture in finely divided carriers to produce powders adapted to be dusted on infected surfaces for the control of bacteria or to be dispersed in water to produce germicidal dispersions. Such powders conveniently may be prepared by dissolving the desired amount of toxicant mixture in a volatile organic solvent, wetting the carrier therewith, and thereafter evaporating off the solvent. Any desired amount of toxicant may be incorporated into the powder in this fashion. Suitable carrlers include talc, diatomaceous earth, bentonite, and the like. Similarly the toxicant composition may be incorporated into ointments or lotions using the conventional carriers and bases and regulating the concentration of the toxicant to meet the requirements for which the ultimate product is designed.

Various coloring materials, perfumes and the like, may be included in the compositions as described provided only that they do not react with either constituent of the mixture or inhibit the germicidal action thereof.

The following examples illustrate the invention but are not to be construed as limiting. In these examples, the amine salts were employed as tinctures prepared by dissolving one gram of the salt in a mixture of 500 milliliters of ethyl alcohol, 100 milliliters of acetone, and 400 milliliters of water, which mixture is hereinafter referred to as the standard solvent. All results are given in terms of one part by weight of the solid amine salt in a stated number of parts by weight of solvent. Similarly, tinctures were prepared of the mercurials and the effectiveness of the latter in terms of dilution refers to the number of parts by weight of solid mercurial in the dilution reported. An exception is found in the case of mercuric chloride where water was employed as the solvent.

EXAMPLE 1 One gram of di-normal-octylamine hydrochloride was dissolved in one liter of the standard solvent as above defined to produce a germicidal concentrate. The effectiveness of this tincture was determined against Staphylococcus aureus at 37 centigrade, according to the method developed by the United States Public Health Service, Hygienic Laboratory of the Food and Drug Administration, United States Department of Agriculture (Circular 198, published December 1931). In this operation, the tincture was found effective at a dilution of one part by weight of amine in 9,000 parts by weight of water.

In further determinations, a similar tincture of Mercarbolide (ortho-hydroxy-phenyl-meruric chloride) and a 0.2 per cent solution of mercuric chloride in water were found to be effective at dilutions of 12,000 and l-500 in water, respectively.

Compositions were prepared in which one gram of Mercarbolide and one gram of amine salt were dissolved in one liter of the standard solvent. The resulting germicidal solution was effective against Staphylococcus aureus at a dilution of 1-40,000 in water, based on the active ingredients in the dilution. A similar effectiveness was found for a mixture of equal volumes of amine salt tincture and the aqueous solution of mercuric chloride.

EXAMPLE 2 A tincture containing 0.1 per cent by weight of normal-tetradecylamine sulfate was prepared and tested against Staphylococcus aureus, substantially as described in Example 1 and found to be effective at a dilution of 1-12,000 in water. When one gram of normal-tetradecylamine and one gram of Mercarbolide were dissolved in one liter of standard solvent, the resulting product was eiiective against Staphylococcus aureus in an aqueous dilution of 140,000. When one gram of normal-tetradecylamine and one gram of mercuric chloride were dissolved in one liter of standard solvent, the resulting product was effective against Staphylococcus aureus in an aqueous dilution of 1-30,000.

EXAMPLE 3 A similar operation was carried out in which a 0.1 per cent by volume tincture of N,N-dimethyl-normal-dodecylamine hydrochloride was employed. This solution was effective against Staphylococcus aureus at a dilution of 16,000 with water. Compositions obtained by mixing in one liter of standard solvent one gram of the amine salt with either one gram of Mercarbolide or one gram of mercuric chloride were found effective against Staphylococcus aureus in aqueous dilutions of 1-40,000 and 1-30,000, respectively.

EXAMPLE 4 Other long-chain alkylamine salts were substituted for those shown in Examples 1, 2 and 3 and combined with the water-soluble mercurial salts to obtain compositions of comparable effectiveness. The following table illustrates the results obtained. The columns are identified as follows:

I. The amine salt used.

II. Maximum effective dilution of atincture of one gram of the amine salt in one liter of standard solvent in terms of one part by weight of the solid amine salt to the stated number of parts by weight of solvent.

III. Maximum effective dilution of a tincture of one gram of the amine salt and one gram of Mercarbolide in one liter of the standard solvent in the same terms as stated for column II.

IV. Maximum effective dilution of a tincture of one gram of amine salts and one gram of mercuric chloride in one liter of the standard v solvent in the same terms as stated for column For purposes of comparison the effective dilution of a tincture of Mercarbolide comprising one gram thereof in one liter of standard solvent and the effective dilution of a 0.2 per cent solution of mercuric chloride are also shown and for convenience placed under columns I and II.

I II III IV Mercarbolide l-2, 000 Mercuric Chloride l-500 normal-Dodecylamine hydrochloride 1-15, 000 H35, 000 1-40, 000 normal-Tctmdccylnminc hydrochlor' c l-l5, 000 1-40, 000 l-25, 000 normal-Hexadecylamine hydrochloride H3, 000 1-25, 000 normal-Octadccylamine hydrochloride 1-3, 000 l-25, 000 N,N-Dimethyl-normal-tridccylamine hydrochloride l-l5, 000 l-40, 000 N,N-Dimethyl-normal-tctradecylamine hydrochloride H), 000 140,000 l-25, 000 N ,N-Dimethyl-normul-hexadccylal-S, 000 140, 000

mine hydrochloride N,N-Di'nethyl-normal-octadecylamine hydrochloride i H3, 000 l-25, 000 1-l0, 000 Dl-norrnal-octylamine sulfate ll2, 000 140, 000 Di-normal-octylaminc acetate l-l2, 000 l-35, 000

EXAMPLE 5 Other compositions which may be similarly employed for the control of Staphylococcus aureus or other representative organisms, such 'as sates Eberthella mm, Epidermophuton interdiqital, et cetera, include the following:

Composition .4

0.1% by weight tincture oi normal-hexadecylamine hydrochloride parts by volume 3 0.1% by weight tincture of Mercarbolide parts by volume 1 Pine oil per cent by weight 0.5

Composition B Di-normal-octylamine acetate 0.1% by weight tincture of N,N-dibutylnormal-tetradecylamine hydrochloride 600 0.1% by weight tincture of Metaphcn (anhydride of 4-nitro-5-hydroxymercuri-ocresol) 400 Composition E Milligrams 0.1% by weight tincture of N-benzyl-normaldodecylamine hydrobromide 300 0.1% by weight solution of mercury oxycyanide 100 The amine salt compounds, as employed in the foregoing examples, may be generically described as the soluble acid salts of alkylamines having the general formula:

RI R-N/ .\R'

wherein R represents an alkyl radical containin at least 8 carbon atoms and each R represents alkyl, aralkyl, such as benzyl, aryl, cycloalkyl, or hydrogen. Representative members of this class of compounds adapted to be employed substantially as shown in the foregoing compositions include secondary-octylamine hydrochloride, 2- ethyl-normal-decylamine hydrobromide, tri-normal octylamine sulfate, N methyl normaltetradecylamine propionate, N,N-dimethyl-normal-octylamine metho-sulfate, and the like.

Other solvents which may be employed as carriers for the compositions of amine salt and mercurial as herein disclosed include methanol, propanol, isopropanol, ethylene glycol, diethylene glycol, carbitol, Cellosolve, methyl Cellosolve, methyl carbitol, acetone, or any mixture of two or more of these solvents or mixtures thereof with water.

I claim: I 1. A germicidal composition having synergistic 5 germicidal eifect against Staphylococcus aureus including as active germicidal ingredients (1) an acid addition salt of an alkyl amine containing at least one alkyl radical having from 8 to 18 carbon atoms, inclusive, and (2) a mercurial selected from the group consisting of mercuric chloride and ortho-hydroxy-phenyl-mercuric chloride.

2. A germicidal composition having synergistic germicidal effect against Staphylococcus aureus including as active germicidal ingredients (1) an acid addition salt of an alkyl amine containing at least one alkyl radical having from 8 to 18 carbon atoms, inclusive, and (2) mercuric chloride.

3. A composition according to claim 2 containing approximately three parts by weight of the amine acid addition salt and fromone to nine parts of mercuric chloride.

4. A germicidal composition having synergistic germicidal effect against Staphylococcus aureus including as active germicidalingredients (1) an acid addition salt of an alkyl amine containing at least one alkyl radical having from 8 to 18 carbon atoms, inclusive, and (2) ortho-hydroxy-phenylmercuric chloride.

5. A composition according to claim 4 containing approximately three parts by weight of the amine acid addition salt and from one to nine parts of ortho-hydroxy-phenyl-mercuric chloride. v 6. A germicidal composition having synergistic germicidal effect against Staphylococcus aureus 35 which comprises approximately 0.1 percent by weight of normal-tetradecylamine sulfate and 0.1 percent by weight of ortho-hydroxyphenyl-mercuric chloride dissolved in a mixture of approximately 50 volumes of ethyl alcohol, 10 volumes of acetone and 40 volumes of water.

HAROLD G. KOLLOFF.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 20,869 Bousquet Oct. 4, 1938 1,688,720 I Klages Oct. 23, 1928 1,919,732 Kharasch July 25, 1932 2,109,143 Wolf! Feb. 22, 1938 2,153,707 Becherer et a1 Apr. 11, 1939 2,216,842 Johnson Oct. 8, 1940 2,293,034 Moore Aug. 18, 1942 2,303,366 Katzman Dec. 1, 1942 OTHER REFERENCES McCulloch, Disinfection and Sterilization," 00 p. 271 (1945), Lee and Febiger, Phila. (Copy in Div. 43.) 

